Keeping aquatic turtles and the aquariums they are housed in clean-looking and stink smell free is easier than most people think.

There are three basic principles to keep in mind when maintaining a turtle tank and keeping it clean. They are water volume, filtration, and maintenance.

Water Volume: Aquatic turtles such as sliders and painteds should have as much swimming water as possible. The basic rule of thumb is to have 10 gallons of water for every inch of turtle shell. Following this general rule, this means that a 1″ hatchling should be in at least 10 gallons of water and a 4″ turtle should be in at least 40 gallons of water.

This estimate accounts for the obvious enjoyment of more water and space to swim in for the pet turtle, but it also compensates for the additional waste that a larger turtle produces. The larger the turtle, the larger it’s poop, the more it sheds (skin and shells, which is just more waste), and since it eats more food too, then it will also tend to leave more uneaten food particles – all, if left in an aquarium will degrade the quality and cleanliness of the tank water. So, more water means more with which to dilute waste and the resulting chemicals (ammonia, nitrites, and nitrates) from the nitrogen cycle.

More water also means less required water changes (translation: more time between water changes) compared to having less water. Lastly, dirt looks smaller and thus less obvious in a larger tank than in a smaller one. So more the more water, the better.

Filtration: Adequate and proper filtration is absolutely mandatory to maintain a clean turtle tank.

Filter Media. Mechanical/physical and biological filter media are absolute essentials. Mechanical filtration takes care of cleaning the turtle tank water of visible dirt: skin, food, etc… Obvious benefits. Chemical filter media on the other hand removes what is unseen, mostly ammonia, nitrates, & nitrites chemicals in the water – which also contribute to smell. So more benefits.

Chemical filtration, usually in the form of carbon/charcoal isn’t necessary for a turtle tank. Unless there is real wood in the tank, such as driftwood or corkbark, then having chemical filtration will be beneficial as it will remove tanins (the brown color that leaches from wood) from the tank water.

Filter strength. A strong filter is needed. Circulation rate/flow rate is what you need to keep in mind. The minimum needed for a turtle tank is for flow rate (in GPH – gallons per hour) to be double the amount of water you have in your aquarium. So, a 100 gallon tank would need filters that can do at least 200 GPH. This means that all the water in the turtle tank passes through the filter at least twice an hour (circulation). Circulation rates of 3 times an hour is even better than just twice, with this example. More is better.

Maintenance. Things get dirty and dirt builds up. A turtle tank should be cleaned regularly. Scrubbing the interior glass and vacuuming/siphoning dirt off the aquarium floor should be done at least once a month. Filters should be thoroughly cleaned every couple of months or whenever it gets clogged enough that flow rate is adversely affected.

Following the above mentioned principles keeps a turtle tank clean. From my experience with a half-filled tank with about 75-85 gallons of water, I did water changes and cleaned the tank once a month and cleaned my filters maybe twice a year. Not a lot of work for a nice clean looking turtle tank.

How about you, how do you keep your turtle aquarium clean?


  1. Great turtle care information. I agree that carbon filtration is not needed for turtle tanks and is more of a money-maker for the pet industry. Powerful biofiltration and water changes are what’s most important!